BCR Diagnostics, Inc. (BCR) proposes to study the feasibility of applying its low-cost biosensor technology to detecting bacteremia in real-time (i.e., less than 5 min). The premise underlying the application is that early diagnosis of bacteremia is crucial because any delay of treatment increases considerably the risk of sepsis syndrome. In the U. S., this life-threatening disease affects more than 250,000 individuals every year with a mortality rate of 20-50% depending on the patient's underlying illness. Currently, laboratory diagnosis of bacteremia is accomplished by blood culture testing, a traditional methodology requiring 24 to 72 hours for completion. BCR's biosensor is based on the LEXSAS (Label-free Exponential Signal-Amplification System); a unique methodology using spores as ultra-sensitive nanodetectors capable of emitting fluorescent light signals when encountering single bacterial cells. The study will consist of three major assignments: Task 1. Adapting and optimizing each of the LEXSAS components using as analyte human blood specimens spiked with Escherichia coli. Task 2. Evaluating performance of the LEXSAS in terms of selectivity, analyte recovery and assay reproducibility. Task 3. Establishing precision of the LEXSAS by comparing the biosensor results with those of conventional culturing. Blood specimens spiked with each of six different bacterial strains will be used as analytes. The proposed study will be initiated using a laboratory version of the LEXSAS that is currently used for identifying bacterially contaminated platelets intended for transfusion. Experiments for Tasks 2 and 3 will be done using a commercial prototype of a highly sensitive bacteriologic biosensor. Other potential commercial applications of the bacteriologic biosensor include environmental surveillance, monitoring blood products intended for transfusion, food and beverage screening, and sterility testing.